Rotary pump.



No. 767,442. PATENTED AUG. 16, 1904. W. W. ROBINSON.

ROTARY PUMP.

APPLICATION FILED AUG.29, 1903.

2 SHBETSSHEET 1 N0 MODEL.

No. 767,442. PATENTED AUG. 16, 1904. W. W. ROBINSON.

ROTARY PUMP.

APPLIGATION FILED AUG. 29. 1903.

N0 MODEL. 2 SHEETS-SHEET 2.

UNITED STATES I Patented August 16, 1904.

PATENT OrFicE.

ROTARY PUMP.

SPECIFICATION forming part of Letters Patent No. 767,442, dated August16, 1904.

Application filed August 29, 1903. Serial No. 171,193. (No model.)

To rtZZ whom it may concern:

Be it known that I, IV ALTER W. ROBINSON, a citizen of the United Statesof America, residing at Chicago, in the county of Cook and State ofIllinois, have invented certain new and useful Improvements in RotaryPumps, of which the following is a specification.

My invention relates to certain new and useful improvements in rotarypumps; and its object is to produce a device of this class which shallbe simple and cheap in construction and highly effective in operation.

To this end my invention consists in certain novel features ofconstruction, which are clearly illustrated in the accompanying drawings and described in this specification.

In the aforesaid drawings, Figure 1 is an elevation of my improved pump,one of the side plates being removed to show the interior construction.Fig. 2 is a vertical longitudinal section through the same. Fig. 3 is asection in the line 3 ,3 of Fig. 2 looking in the direction of thearrow. Fig. 4 is a perspective view of the gate; and Fig. 5is aviewsimilar to Fig. 1, but showing the circular piston and gate in differentpositions.

Referring to the drawings, A is a chamber made in the form of a flatcylinder and hav' ing pipes B O extending from it. One of these pipes isan inlet-pipe and the other an outlet-pipe; but as this pump, like mostrotary pumps, can be run in either direction either pipe may serveeither of these purposes. In the center of the chamber A is a shaft D,upon which is eccentrically mounted a circular piston E, keyed againstrotation by a key e. The piston is of such size that the point farthestremoved from the shaft is in close contact with the wall of the cylinderA, and the thickness of the piston is the same as that of the cylinder,so that as the shaft D is rotated and thepiston E moves around thechamber any fluid therein contained will be forced to move with it.

A hollow tube F is provided, extending radially from the chamber A, andin this tube is a gate G. A cap F closes the top of the tube F, and aspring Gr holds the gate G, which is made with a hollow center, incontact with the piston E. A small perforation g is provided. at thelower end of the gate G, through which a lubricating substance can pass.The gate is in practice filled with some thick lubricating material. Thepeculiar feature of this gate is that it is circular in crosssection andthat it is beveled at its point, as shown in the drawings. In buildingapump it is much easier to use a circular gate than a gate of any otherform, for the reason that the socket in which it reciprocates can bebored out without any great difficulty, while a hole of any other shapeis much more expensive to make. The difficulty, however, with acylindrical gate squared at the bottom is that as the piston rotates theline of contact of the gate therewith swings to one side from the otherof the diameter, and a by-pass is provided through which the fluid inthe pump can pass from one side of the gate to the other, and so not beforced out of the outlet-pipe. Some means must therefore be provided forkeeping the gate in contact with the piston upon a line diametrical ofthe gate, and this is accomplished by beveling the end thereof. To betheoretically perfect, the gate should be beveled with two faces meetingin amath- 'ematical line, the angle of the bevel being at least enoughto make the faces tangent when the periphery of the piston presents thesmallest angle to a line running longitudinal of the gate. In practice,however, a gate beveled to a mathematical line would wear out toorapidly,and consequently the point is slightly rounded, but is of suchshape as to keep the line of contact of the piston upon the peripherysubstantially at the diameter of the gate. When the gate is constructedin this manner with a beveled end, it is not necessary to provide meansfor preventing the gate from rotating in the socket provided for it, forthe reason that the pressure of the spring G, which forces the gate intocontact with the piston, makes it very difiicult for it to occupy anyother position than that shown in the drawings while the piston is inrotation. In fact, with the piston rotated ninety degrees from theposition shown in Fig. 1 a considerable amount of extra compression ofthe spring must be effected before the gate can be rotated. The bevelingof the point of the gate therefore has two very desireable fea tures.First, it keeps theline of contact practically diametrical and preventsleakage past the gate, and, second, it prevents rotation of the gate.

I realize that considerable variation is possible in the details of thisconstruction without departing from the spirit of the invention, and Itherefore do not intend to limit myself to the specific form hereinshown and described.

claim as new and desire to secure by Letters Patent- 1. In a device ofthe class described,the combination. with a suitable chamber havinginlet and exhaust ports, of a rotatable piston eccentrically mountedtherein, and a cylindrical spring-pressed gate beveled at its lower end,

' bination with a chamber and inlet and exhaust ports connectedtherewith, of a rotatable piston eccentrically journaled therein, acylindrical gate extending radially from the chamber, means for holdingthe gate in contact with the piston, the gate being provided with abeveled lower end, and no means being provided other than the beveledsurfaces for preventing the rotation of the gate.

In witness whereof I have signed the above application for LettersPatent at Chicago, in the county of Cook and State of Illinois, this24th day of August, A. D. 1903.

WVALTER WV. ROBINSON.

Witnesses:

S. BLIss, M. B. BLIss.

